RICHARDSON, Texas (Aug. 8, 2002) - A
biophysicist and a mathematician at The University of Texas at Dallas (UTD) have
been awarded a $1.2-million grant from the National Institutes of Health to
study site-specific recombination of DNA, a class of natural gene-splicing
activities in which segments of a DNA sequence are rearranged.

In addition to rearranging the DNA
sequence, these splicing events are capable of changing the topology of a DNA
molecule. For example, recombination of DNA sequences on a circular molecule
can cause the molecule to become knotted or can generate smaller DNA circles
that are linked together multiple times.

Deoxyribonucleic acid, or DNA, is a long molecule
shaped like a spiral staircase which stores the primary genetic information of
a living organism.

The research, to be conducted over the
next four years by Dr. Stephen D. Levene, associate professor, Molecular and
Cell Biology, and Dr. Isabel Darcy, assistant professor, Mathematical Sciences,
could have broad implications in the fields of biotechnology and biomedicine.

"Site-specific recombination is essential
for many biological processes, such as gene amplification, the generation of
antibodies and the transposition of drug-resistant genes," said Levene. "Yet,
there is much about the process that is unknown. It is therefore imperative that
we begin to understand the physical and chemical factors that govern recombination."

According to Levene, the research done at
UTD may prove helpful in experimental gene targeting using frog and mouse
genomes and, in the future, could impact human gene therapy.

Darcy, who is a mathematician working in
the area of knot theory, will utilize an approach to studying recombination
based on a technique known as tangle analysis. This will involve the use of
mathematical and computational tools to help determine the shape of DNA
molecules bound to recombination proteins. Information regarding the mechanism
of recombination can be obtained by looking at the types of knots produced by
these proteins in a DNA molecule.

"My research involves solving systems of
equations," said Darcy. "The equations are determined by the types of knots
produced by protein action. Thus, the equations I work with involve knots
instead of numbers. The solutions to these equations represent the topological
shape of the DNA bound by the protein."

The investigators will use both electron
and atomic force microscopy in their research to image DNA molecules and the
enzymes acting upon them.

Levene holds a Ph.D. degree in chemistry
from Yale University. He joined UTD in 1992 and teaches graduate and
undergraduate classes in molecular biology and biophysics. Darcy earned a
Ph.D. degree in mathematics from Florida State University. She
has been a member of the UTD faculty since 1999 and teaches classes in
mathematics, including computational biology and topology, to graduate and
undergraduate students.

About UTD

The University of Texas at Dallas, located at the convergence of Richardson, Plano and Dallas in the heart of the complex of major multinational technology corporations known as the Telecom Corridor , enrolls more than 7,000 undergraduate and 5,000 graduate students. The school's freshman class traditionally stands at the forefront of Texas state universities in terms of average SAT scores. The university offers a broad assortment of bachelor's, master's and doctoral degree programs. For additional information about UTD, please visit the university's Web site at www.utdallas.edu.